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A 38-kilobase pathogenicity island specific for Mycobacterium avium subsp. paratuberculosis encodes cell surface

Janin Stratmann1, Birgit Strommenger, Ralph Goethe

  • 1Institute for Microbiology, Department of Infectious Diseases, School of Veterinary Medicine, Hannover, Germany.

Infection and Immunity
|February 24, 2004
PubMed

Insights

Researchers discovered a new ABC transporter operon (mpt) specific to Mycobacterium avium subsp. paratuberculosis. This operon, along with flanking genes, forms a unique 38-kb locus suggesting a pathogenicity island in this bacterium.

Area of Science:

  • Microbiology
  • Genomics
  • Bacterial Pathogenesis

Background:

  • Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease in ruminants.
  • Understanding MAP-specific genetic elements is crucial for disease control.

Purpose of the Study:

  • To identify and characterize novel genetic loci specific to MAP.
  • To investigate the function and expression of identified genes.

Main Methods:

  • Representational difference analysis (RDA) for identifying unique DNA sequences.
  • Functional genomics and gene cluster analysis.
  • Western blot and phage-peptide library screening for protein expression and localization.

Main Results:

  • Identification of a novel 38-kb MAP-specific locus containing an ABC transporter operon (mpt) and siderophore-related genes.
  • MptC was detected in the MAP envelope fraction.
  • MptD protein was confirmed as surface-exposed using phage display and capture PCR in milk samples.

Conclusions:

  • The identified 38-kb locus, including the mpt operon, represents a MAP-specific pathogenicity island.
  • The surface-exposed MptD protein is a potential diagnostic target for MAP detection.

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